Weapon having partible firing chamber

ABSTRACT

A semi-automatic or automatic weapon provided with a split or partible firing chamber, adapted to be fed laterally with cartridges and operating in conjunction with a reciprocating bolt mechanism having an exceptionally short stroke, whereby the weapon may be fired at a high rate. The chamber is composed of a pair of complementary sections which in the course of each cycle of rotation or reciprocation, depending upon the nature of the weapon, are caused by associated cams to first separate to receive a laterally-fed incoming round, and thereafter to draw together to define a cavity enclosing the round, at which point the bolt mechanism acts to engage and fire the round in the chamber, the case then being extracted and ejected.

finite States Patent 1 [111 3,782,242

Angell et a1. Jan. 1, 1974 1 WEAPON HAVING PARTIBLE FIRING 64, W G u tqgtaLa "ill-LAM CHAMBER FOREIGN PATENTS OR APPLICATIONS [76] inventors: Robert H. Angell, 514 E. 88th St., 639,712 7 1950 Great Britain 89/33 MC New York City, N.Y. 10028; Robert 20,275 1 1914 Great Britain 89/155 S. Frielich, 396 Broome St., New York City, NY. 10013; James P. Angel], 1 119 N. Jackson, River Forest, 111.

[22] Filed: Feb. 9, 1972 [21] Appl. No.: 224,661

[52] U.S. Cl. 89/11, 89/12, 89/24, 89/33 MC [51] Int. Cl. F4ld 7/02 [58] Field of Search 42/2, 5, 9, l4, 15, 42/23, 24, 32, 33, 39.5; 89/4 A, 9,11,12,13 R, 13 A, 17, 22, 23, 24, 33 MC, 155, 156, 157, 160

[56] References Cited UNITED STATES PATENTS 165,318 7/1875 Farrington..... 89/33 MC 30,714 11/1860 Boynton 42/15 33,813 11/1861 McCord et a1. 89/33 MC Primary ExaminerStephen C. Bentley Attorney-Michael Ebert 5 7] ABSTRACT A semi-automatic or automatic weapon provided with a split or partible firing chamber, adapted to be fed laterally with cartridges and operating in conjunction with a reciprocating bolt mechanism having an exceptionally short stroke, whereby the weapon may be fired at a high rate. The chamber is composed of a pair of complementary sections which in the course of each cycle of rotation or reciprocation, depending upon the nature of the weapon, are caused by associated cams to first separate to receive a laterally-fed incoming round, and thereafter to draw together to define a cavity enclosing the round, at which point the bolt mechanism acts to engage and fire the round in the chamber, the case then being extracted and ejected.

5 Claims, 14 Drawing Figures PATENTEDJAH 11914 I 3382.242 sum 10F s PAIENIEUJAN 1 mm 11W MI 0 II JJQ lh f L T /g PAIENTEDJAH 1 I974 lllhllll lrfi wm WEAPON HAVING PARTIBLE FIRING CHAMBER BACKGROUND OF THE INVENTION This invention relates generally to semi-automatic and automatic weapons, and in particular to a weapon having a split or partible firing chamber adapted to be fed laterally with cartridges.

The operating power of many automatic weapons such as machine guns or aircraft cannon capable of sustained firing, is often derived from the force generated by the explosion of the propellent charge. In modern day weapons, two techniques are employed for deriving operating power from the explosion. The first is known as recoil actuation and depends on the rearward thrust of the recoiling mass. The second, labeled as gas operation, makes use of the pressure generated in the bore by the expanding gas of the progressively burning charge. It is also known to operate semi-automatic and automatic weapons by external power sources, such as electric motors.

The present invention is applicable to various types of semi-automatic as well as automatic weapons, which operating power is derived from the explosive force or from an external motor and wherein cartridges are fed into a firing chamber for subsequent ignition. The primary concern of the invention is with respect to the structure of the chamber and the manner of feeding cartridges therein.

In a conventional weapon arrangement, the chamber is in the form of a hollow housing whose internal cavity conforms to the size and shape of the cartridge to be fired. The front end opening of the chamber lies in registration with the rifled bore of the weapon barrel, while the rear end opening thereof is in registration with a retractable bolt. The cartridge is admitted through a breech casing and is caused to first occupy a position behind the chamber in axial alignment with the rear opening thereof, the cartridge then being rammed into the chamber by the bolt to occupy its firing position.

The need to feed cartridges to a rear position in axial alignment with the chamber and to ram the cartridge into the chamber the full length thereof, is an important factor in determining the firing rate of the weapon, for however well designed the system, existing feed requirements with conventional chambers and bolt mechanisms are such as to slow down the, firing rate and thereby reduce the effectiveness of the weapon.

The bolt stroke in a conventional reciprocating weapon must be at least as long as the entire round and usually is considerably longer. In order to speed up the operation, one must accelerate bolt movement which, because of the long stroke, produces a sustained impact on firing. This tends to wear the operating mechanisms. While attempts have been made to lighten, the bolt to increase its velocity, this weight reduction is at the expense of the durability of the bolt and acts to shorten its operating life.

In weapons having a revolver action combined with a reciprocating bolt action, the revolution of the cylinder can be accomplished by the same methods employed in a conventional revolver, and the bolt can be operated in the same way as in ordinary reciprocating action. However, in this type of weapon, one may provide a so-called short bolt action wherein the bolt moves back only through a sufficient distance to be in a position to engage the next IOUIId'.'ThIS means that the bolt only partially extracts the cartridge case and the completion of extractionand ejection is delayed until the rotation of the cylinder moves the cartridge case to one side of the bolt mechanism. Since the distance moved by the bolt need only be as great as the length of the exposed portion of the projectile plus a part of the cartridge case, the bolt stroke is about half the length of the complete round, as distinguished from the stroke entailed in a conventional weapon in which the stroke must be at least as long as the length of the round.

The advantage of the short bolt stroke in the revolver action-reciprocating bolt weapon is that the bolt motion can occur at relatively low velocity, as a result of which accelerations and shocks to which the bolt is subjected during firing are well below the critical and limiting values experienced in ordinary high-rate of fire reciprocating actions. Therefore, the short-stroke bolt mechanism is capable of producing very high cyclic rates without the difficulties usually associated with sliding bolt mechanisms.

SUMMARY OF THE INVENTION In view of the foregoing, it is the primary object of this invention to provide an automatic or semiautomatic weapon having a split or partible firing chamber operating in conjunction with a bolt mechanism having an exceptionally short stroke.

Among the significant advantages of the invention are the following:

1. With a partible chamber which may be expanded to receive a laterally fed round, and then closed to accommodate the round, it is no longer necessary to allow for space in the rear of the chamber to receive-an incoming round through a breech casing; hence the weapon may be made more compact and lighter in weight.

2. Because the round is directly fed into the chamber rather than being rammed therein from the rear, the resultant stroke length of the bolt mechanism may be made very short, the length being even shorter than that of the short-stroke bolt mechanism in revolver-type automatic weapons.

3. Because of the exceptionally short stroke of the bolt mechanism, wear is reduced substantially, and the bolt may be operated at a relatively low velocity to minimize shock effects.

4. The invention makes possible, unusually high cycle firing rates, using ordinary bolt mechanisms.

5. The invention also simplifies extraction and ejection actions in the weapon.

More specifically, it is an object of this invention to provide an automatic or semi-automatic weapon which may be explosive-force or power-operated and wherein the rotation or reciprocation of the partible chamber is exploited to bring about an expansion of the chamber to laterally receive an incoming round.

Also, an object of the invention is to provide a weapon of the above type which may be constructed at relatively low cost, and which functions efficiently and reliably.

Briefly stated, these objects are accomplished in a weapon in which the firing chamber is composed of a pair of complementary sections that, in the course of a rotary or reciprocatory cycle, engage cam elements causing the sections to first separate to receive a laterally fed incoming round, and to then draw together to enclose the round, at which point the bolt mechanism acts to engage and fire the round in the chamber, after which the case is extracted and ejected, and the cycle repeated.

OUTLINE OF THE DRAWINGS For a better understanding of the invention, as well as other objects and further features thereof, reference is made to the following detailed description to be read in conjunction with the annexed drawing wherein:

FIG. 1 is a perspective view of a power-operated automatic weapon having a partible chamber in accordance with the invention, the chamber being shown in the cartridge loading state;

FIG. 2 is a perspective view of the same chamber shown in the closed state;

FIG. 3 is a transverse section taken through the chamber shown in FIG. 1;

FIG. 4 is a transverse section taken through the chamber shown in FIG. 2.;

FIG. 5 is a transverse section taken through the chamber in the cartridge ejection state;

FIG. 6 is a longitudinal section taken in the plane indicated by line 6-6 in FIG. 1, and showing the cartridge in the closed chamber before it is rammed into position by the bolt;

FIG. 7 is the same as FIG. 6 except that in this instance, the cartridge is in position for firing;

FIG. 8 is an elevational view of an automatic weapon using the recoil principle and having a partible chamber in accordance with the invention, the chamber being shown in the cartridge loading state;

FIG. 9 is the same as FIG. 8, except that the chamber is closed about a cartridge;

FIG. 10 is a longitudinal section taken through the automatic weapon shown in FIG. 9;

FIG. 11 is a transverse section taken in the plane of line 11-11 in FIG. 10;

FIG. 12 is a section taken in the plane indicated by line l2-l2 in FIG. 11;

FIG. 13 is a transverse section taken in the plane indicated by line 1313 in FIG. 10; and

FIG. 14 is a transverse section taken in the plane indicated by line 1414 in FIG. 10.

DESCRIPTION OF THE INVENTION Referring now to the drawing and more particularly to FIGS. 1 to 7, there is shown an automatic weapon whose operating power is derived from a motor M which serves to rotate a firing drum generally designated by numeral 10, and a barrel 11 extending axially therefrom, as well as to provide power to all other operating functions including the reciprocating movement of a bolt mechanism 12.

Firing drum 10 is constituted by a hollow cylindrical body 13 whose end portions 14 and 15 serve as bearings and fit within circular openings in a pair of parallel receiver plates 16 and 17, respectively. The rear end of barrel 11 is threadably received in a circular recess in the end portion 14 of the chamber body. It will be appreciated, however, that other known arrangements may be used to provide a replaceable barrel. Mounted on bars extending between receiver plates 16 and 17 are a pair of round stationary earns 18 and 19. The cams are symmetrically disposed relative to chamber body 13 on diametrically opposed sides thereof and are slightly spaced from the body, whereby the body is free to rotate.

While body 13 has been described as cylindrical, in practice it may have other formations used in weapons such as an octagonal or any other shape.

Formed in chamber body 13 at diametrically opposed positions are two elongated openings 20 and 21 which are occupied by a pair of complementary wing sections 22 and 23, respectively. The wing sections are maintained by wire springs 22A and 23A in their retracted state in which they protrude from openings 20 and 21. In this condition, the protruding wing sections are simultaneously, in the course of rotation of the chamber, engaged by stationary earns 18 and 19 and are forced inwardly thereby until they touch each other, in which condition the wing sections are in their operative state to define the chamber cavity for enclosing a round to be fired.

When complementary wing sections 22 and 23 are retracted and spaced apart in their retracted state, as shown in FIGS. 1 and 3, the inner ends thereof are aligned with the banks of a third opening 24 in chamber body 13. This opening lies midway between wing openings 20 and 21 and serves as a port for admitting a round 25 when the angular position of the chamber body in the course of rotation lies in registration with a cartridge-feeding mechanism (not shown).

As the chamber body continues to rotate counterclockwise, the wing sections 22 and 23 are engaged by the stationary cams 18 and 19 and are forced inwardly, until a point is reached, as shown in FIGS. 2 and 4, at which the inner ends of the wing sections touch each other. The inner ends hav complementary concave formations to define a cavity enclosing the round admitted into the chamber.

Projecting into the cavity defined by the wing sections 22 and 23 in their operative state is an ejector pin 26, which is urged therein by a spring 27. When a round lies within the closed wings, the ejector pin 26 is forced out of the cavity by the round. But when, as shown in FIG. 5, after the cartridge 25 has been fired to discharge the projectile 25A thereof and the case 258 thereof remains in the cavity, this case is ejected by ejector pin 26 when the wing sections have again been retracted and port 24 is now in line with an ejector outlet at a position removed from the feed-in position shown in FIG. 3.

Thus, in FIG. 3, the axis of port 24 is at 45, at which angle a round is admitted into the chamber body between the retracted wings. In FIG. 4, the axis of port opening 24 is at 0, at which angle the round is confined between the closed wing sections in readiness for firing, while in'FIG.'5, the axis of port 24 is at 225, at which position the wings are again retracted to permit ejection of the casing.

Bolt 12, which is supported for reciprocal motion relative to the body 13 and the firing chamber therein, is provided with a pair of longitudinally extending keyways 12A and 12B, which as shown in FIGS. 1 and 6, are in line with chamber guide pins 29 and 30. These pins permit sliding motion of the bolt, but prevent rotation thereof.

FIG. 6 shows the round 25 just admitted into the cavity defined'by the wing sections. The round, in its initial position, is disposed with its projectile 25A displaced from the firing position at the rear end of the bore of the barrel 1 l, with the rear of its case 258 adjacent the free end of the bolt. Bolt 12 is then advanced to push the round into its firing position, as shown in FIG: 7, at which point it will be seen that ejector pin 26 engages the surface of casing 258 and is urged thereby out of the cavity.

The round is fired by means of firing pin 28, which is coaxially positioned within bolt 12, and acts to strike the primer at the rear of the round. When the round is at its firing position, operation of the system is such as to lock the bolt in position. This is accomplished by means of locking lugs 12C and 12D on the bolt, as shown in FIG. 1. With ignition, the projectile is propelled through the barrel, the gases resulting from the explosion being dissipated from the barrel.

After firing, the rotation of the chamber and the bolt effects disengagement of the locking lugs, permitting retraction of the bolt, and extraction thereby of the case to return it to its initial position. As the chamber continues to rotate, the wing sections separate and the case is ejected at the ejection position, after which the port is again aligned with the cartridge feed position, and a new round admitted for the next firing cycle.

For the foregoing, it will be evident that the necessary stroke for this bolt is exceptionally short. The necessary reciprocal travel of the bolt is from the initial position shown in FIG. 6, at the rear of the round admitted into the chamber to the firing position shown in FIG. 7, and return, a very short distance, as compared to prior-art arrangements.

With this exceptionally short stroke, the firing rate may be extremely fast' and the practical advantages mentioned previously in the summary of the invention, are gained. v

In FIGS. 8 to 14, there is shown a weapon operating on the short-recoil principle, the weapon including a barrel 30, a barrel extension 30A, and a chamber 31 constituted by two complementary sections 31A and 313. The sections in FIG. 8 are shown in their retracted state, and in FIG. 9, in their operative or closed state.

In the conventional short-recoil system of operation, the barrel and bolt remain locked and recoil together for a short distance, until the power gas pressure has dropped to a safe limit. The recoil movement is then utilized to unlock the bolt and after unlocking, the barrel is stopped while the bolt continues to move to the rear until the opening between the barrel and bolt is sufficient to permit feeding.

It would be possible for the bolt to complete this movement merely by virtue of the momentum it possesses at the instant of unlocking, but in short-recoil weapons, in order to speed up operation, the bolt is given additional impetus by means of an accelerating device which transfers energy to the bolt from the barrel during the short time that the barrel is still moving to the rear after unlocking. Also, unlocking usually occurs before the residual pressure reaches zero, and therefore the bolt receives an additional impulse from blowback action.

Since the bolt in a conventional short-recoil type of weapon must move to the rear until a sufficient opening exists to admit a new round, the stroke of the bolt is relatively long, this factor limiting the cyclic speed of the weapon and having other serious disadvantages, as previously mentioned. In the present invention, the round is admitted into the partible chamber of the weapon laterally, and the bolt is locked to the chamber and reciprocates therewith during recoil action.

The chamber sections 31A and 31B cooperate with two sets of stationary cams 32, 32" and 32", and 33, 33", 33", respectively. The outer surfaces of chamber sections 31A and 318 have an undulating profile formed by alternate troughs and flattened peaks, whereas the inner surface thereof is contoured to define a cavity for accommodating a round when the sections are brought together.

When, as shown in FIG. 8, the two sets of cams engage the troughs on the outer surfaces of chamber sections 31A and 31B, the sections are separable to permit the lateral admission of round 34 so that the head of the case is introduced into the T-slot 35 of the bolt 36. The bolt, which is locked to the chamber sections, then moves forwardly under the force of a rear spring to ram round 34 into its firing position. The recoil action is such that the moving chamber is shifted relatively to the sets of fixed cams, so that they now make contact with the crests of the section profile and force the sections together to define the chamber cavity, whereby the round is now set to be fired as all components are locked together.

Ignition is effected by a firing pin 37, as best shown in FIGS. 9 and 12, the case being subsequently ejected by means of an ejector pin 38. Alternatively, a standard electrical ignition system may be used for the same purpose.

Thus, as in the case of the motorized weapon shown in FIGS. 1 to 7, therecoil-type weapon shown in FIGS. 8 to 14 has a split chamber which separates to receive a round and then closes about the round to define a cavity for firing. Since it is the chamber in the recoil weapon which reciprocates, not the bolt, relative to the chamber, the chamber need merely move a distance sutficient to advance the laterally-admitted round from its initial position to its firing position, as a consequence of which the firing rate may be very rapid While there have been shown and described, preferred embodiments of a semi-automatic or automatic weapon provided with a split or partible firing chamber in accordance with the invention, it will be appreciated that many changes and modifications may be made therein without, however, departing from the essential spirit of the invention.

For example, instead of a pair of complementary wing sections, as shown in FIG. 1, one may use three or more complementary sections which are retractable to open the chamber and which when brought together by a cam action or other means, serve to define the chamber cavity. Also, in place of stationary cams operating in conjunction with a rotatable chamber, the cams may be movable to effect closure of the wings.

In practice, cam movement may be effected electromagnetically or by gas propulsion. Also, though the mechanisms have been described herein in conjunction with standard ammunition in the form of cylindrical cartridges, it is equally operable with other known forms, such as ammunition having a triangular or other non-circular cross-section, in which event the inner profile of the chamber is designed to conform to the shape of the ammunition. TI-Ie invention is also applicable to multi-barrel weapons, such as those of the Gatling type.

I claim:

l. An automatic or semi-automatic weapon having a rapid firing action, said weapon comprising:

a. a barrel,

b. a firing chamber coupled to the rear of the barrel for accommodating a round having a projectile and a case, said projectile when fired passing through said barrel, said chamber having a pair of complementary sections which are retractable with respect to each other along a common transverse axis to define a pair of identical diametrically-opposed gaps to admit a round fed laterally into the chamber along an axis normal to said transverse axis to occupy an initial position therein, said sections when closed defining a cavity enclosing said round, said chamber being formed by a rotatable hollow cylinder having opposing openings therein which are occupied by a pair of retractable wings constituting said complementary sections and cooperating with a pair of stationary cams whereby as the cylinder rotates, the wings engage said cams and are caused to alternately retract and close,

bolt arranged to engage the rear of the case of the round in the chamber, and

d. means for cyclically retracting and closing said sections in an operating sequence in which said round is admitted between the retracted sections.

2. A weapon as set forth in claim 1, wherein said weapon is motor-operated.

3. A weapon as set forth in claim 1, wherein said chamber cylinder further includes a breech disposed between said wing openings in registration with said gaps to admit a round laterally into said chamber and to permit ejection of the case.

4. A weapon as set forth in claim 1, further including means to lock the bolt just before the round is fired and to thereafter release the bolt.

5. A weapon as set forth in claim 1, wherein said round is admitted into the firing chamber through one of said gaps and further including a spring-biased ejector pin extending into said cavity through the other of said gaps, said pin being forced out of the cavity when the round is admitted and after firing, re-entering the cavity to eject the case of the round.

Patent No. 3 r 782 1 242 Dated January 1, 1974 I et 211. Inventor(s) Robert Angel]- I It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 14 ."chamber," should have read chamber body,

Column 4, line 33 "-hav" should have read have Column 5, line 23 "For" should have read From Column 6, line 61 "THe" should have read The Signed and sealed this 9th day of April 1971,.

(SEAL) Attest:

0; MARSHALL DANN Commissioner of Patents EDWARD M.FLETQHER,JP.. Attesting Officer Patent 3,782,242 Datd January 1, 1974 6 et 211. Inventor(s) Robert H. Angell It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 14 "chamber, should have read chamber body,

Column 4, line 33 "hav" should have read have Column 5, line 23 "For should have read From Column 6, line 61 "'I'He" should have read The Signed and sealed this 9th day of April 19%,, i

(SEAL) Attest: EDWARD PLFLETCHERJH. I 0. MARSHALL DANN Attesting Officer I Commissioner of Patents 

1. An automatic or semi-automatic weapon having a rapid firing action, said weapon comprising: a. a barrel, b. a firing chamber coupled to the rear of the barrel for accommodating a round having a projectile and a case, said projectile when fired passing through said barrel, said chamber having a pair of complementary sections which are retractable with respect to each other along a common transverse axis to define a pair of identical diametrically-opposed gaps to admit a round fed laterally into the chamber along an axis normal to said transverse axis to occupy an initial position therein, said sections when closed defining a cavity enclosing said round, said chamber being formed by a rotatable hollow cylinder having opposing openings therein which are occupied by a pair of retractable wings constituting said complementary sections and cooperating with a pair of stationary cams whereby as the cylinder rotates, the wings engage said cams and are caused to alternately retract and close, c. bolt arranged to engage the rear of the case of the round in the chamber, and d. means for cyclically retracting and closing said sections in an operating sequence in which said round is admitted between the retracted sections.
 2. A weapon as set forth in claim 1, wherein said weapon is motor-operated.
 3. A weapon as set forth in claim 1, wherein said chamber cylinder further includes a breech disposed between said wing openings in registration with said gaps to admit a round laterally into said chamber and to permit ejection of the case.
 4. A weapon as set forth in claim 1, further including means to lock the bolt just before the round is fired and to thereafter release the bolt.
 5. A weapon as set forth in claim 1, wherein said round is admitted into the firing chamber through one of said gaps and further including a spring-biased ejector pin extending into said cavity through the other of said gaps, said pin being forced out of the cavity when the round is admitted and after firing, re-entering the cavity to eject the case of the round. 